Standard office copiers have proliferated throughout the business world for copying original documents onto plain pieces of paper. Many such machines on the market accomplish this task with a number of manufacturing companies supplying such apparatus to the general marketplace.
Previously, however, standard office copiers normally made copies of sheets of paper ranging from 81/2.times.11 to 11.times.14 inches (or in foreign countries, standard paper known as A4 paper). Other copiers had to be used for copying engineering type drawings because of the fact that extra optics are needed to reduce the large size engineering drawings down to paper, for example, the size of 14 inch by 17 inch paper. Certain customers desire the facility of copying both office type documents and engineering type documents at the same time, to remove the necessity for having two, separate and distinct, copiers.
Xerox Corporation, a large manufacturer of plain paper copiers, has marketed the 3107 model office copier for several years. This copier is a standard office copier which copies those office documents set forth above. Certain 3107 and other Xerox copier customers desire to have a copier which could copy larger sized documents while not necessitating the purchase of a second copier for such large document copying. Thus, it was presented that a movable document handling system placed on top of the 3107 machine, modified to accommodate the extra weight, optical path, etc., could be utliized to allow for standard office copying at one end while allowing for large document copying at the other end.
According to the present invention, a movable document handling system, or module, is utilized on a modified standard office copier. When the document handling module is moved away from the platen glass area, the document handling module equipment is disabled and the office copier may be used as a standard copier. When, however, the document handling module is moved over the platen glass, other optics and document handling apparatus are now energized and the standard office copier is now converted into a large document copier. The document handling module can be opened in either of the two positions for service and maintenance. Dual sets of gas spring apparatus is provided, wherein one or both gas springs in each set are in use for increased mechanical assistance in raising the document handling module when in place over the standard glass platen area. When the module is positioned away from the platen area, less mechanical assistance is required due to the shift on the module's center of gravity and only one in each dual sets of gas springs are allowed to actuate, said selective operation being controlled by the requisite mechanical linkages and assemblies.